The Forestry Forum

General Forestry => Drying and Processing => Topic started by: woodjunky on December 10, 2014, 10:52:35 PM

Title: All the experienced kiln driers. Solar kiln or power?
Post by: woodjunky on December 10, 2014, 10:52:35 PM
Living up by Lake Superior. The hot season is short. What does it cost to heat a kiln for a batch of 2-3000 board feet?  Are they natural gas, or mainly electric powered? Wood powered? And what about hybrids? Solar kiln with wood stove or small electric heater to keep temps up? Im all about efficiency. But complete solar is just painstakingly slow up north i imagine?
Anyone make a hybrid kiln before?
Title: Re: All the experienced kiln driers. Solar kiln or power?
Post by: WDH on December 11, 2014, 07:38:43 AM
I am running a Nyle L53 dehumidification kiln.  It can dry a load up to 1000 BF.  My electric bill has averaged $100 over the last 11 months.  Some of this cost, however, is attributed to running my planer as most of the boards that get dried, also get skip planed. 
Title: Re: All the experienced kiln driers. Solar kiln or power?
Post by: GeneWengert-WoodDoc on December 11, 2014, 08:06:20 AM
How many times have you heard the weather forecast state "Colder near the Lake?"   And of course, you also know that with a NW or N wind, you also get moisture off the Lake--higher humidity in the "warmer" months and snow in the cooler months.  A lumber pile covered with snow is not going to dry much at all and in fact may even gain moisture.  So, I am sure that you know you know your climate is not very attractive for effective air drying.

As far as solar drying goes, it is not impossible, but the cold weather with the fog that you sometimes have and your more northern location all make the solar drying not as attractive as it is further south, especially south of you 500 miles or more.  In fact, your "good" solar drying season is probably only four months a year.  But you probably want dried lumber more often than just four months.

In the design of most solar kilns, the collector is an integral part of the roof.  As a result, you will find that the solar losses through the collector when the sun is not shinning are very large.  Hence, a hybrid kiln is not realistic.  If you make a solar kiln with an external collector--that is, a well insulated box for the kiln and a separate collector that you can thermally isolate from the kiln and then use auxiliary heating in the kiln as needed, you would actually be much better off going 100% with the auxiliary heat, as the solar input over the year would be so small.

So, for serious drying, you really need to think about a small kiln or two.  Two small kilns are better than one large one as you can dry different species and different MCs, etc.  The power plant can be an electrical DH unit, where all you have to do is plug it in.  There is nothing technically wrong with having a small heating plant using natural gas, propane or oil, but then you have to purchase and maintain this power plant--something most small operations would not find attractive.  Because of your cold climate, if the kiln is a stand-alone unit exposed outside (instead of inside a heated building), you need to insulate the walls, floor, foundation and roof very, very well.  I know that NYLE used to sell plans and then if you bought one of their units, the price of the plans could be deducted from the DH price.  Some people use 18-wheeler reefers, but they are not insulated well enough for your climate.

So this is just a first look at what you should consider.  One other key is to get a loan for this equipment and keep your cash available for paying bills when sales are slow, purchasing a variety of lumber, setting up a store or having a delivery truck, etc.  Sales are usually not the same every month, so cash is important.

Also, when figuring out where you want the kiln, always think about where additional kilns would go, so that the first kiln is not in the wrong place as your business expands.

Having a small planer available can be really helpful.

And a final thought is that you will be surprised on how much time you will be spending on marketing and seller KD lumber.  In fact, you might want to make a connection with a retail outlet in Madison, Milwaukee or even Chicago to help move your lumber and generate income.

Title: Re: All the experienced kiln driers. Solar kiln or power?
Post by: Ga_Boy on December 12, 2014, 07:06:12 AM
Here are some questions that should help you decide which technology to use.

Is this a business or hobby?  If a hobby, time and production rate is not a major factor.  If a business, it's all about time and production rate.
These questions assume you will be drying lumber for the commercial market.  A commercial market could be wholesale or retail.

Do you have access to biomass (firewood) for fuel?  If so, an outdoor wood boiler or water heater is worth doing a cost consideration for a conventional kiln.

Do you have a separate power meter at your shop?  If so, a dehumidifier kiln is worth doing a cost consideration.  If you go with a DH, and you do not have a separate meter, you should consider adding the separate meter and factor in the cost of adding the meter.  You will need the meter to track energy costs. 

Compare the DH to the conventional kiln.  Remember to factor in you will be dealing with very cold/frozen material.  This will impact your energy use.

Do you plan to dry thicker 8/4, 10/4, 12/4 material?   This will impact your operation time and energy costs to dry thicker materials.  Here is where Gene's comment about possibly having 2 kilns would also apply.  With this said, you do not have to start with 2, start with one and grow to 2, 3 or what your production/sales support.

If others have considerations that I did not list, please add them.

Title: Re: All the experienced kiln driers. Solar kiln or power?
Post by: AK Newbie on December 12, 2014, 11:45:12 AM
Being in Alaska I have wondered the same thing.  Although my needs would only be for hobby purposes.  Gene your thoughts as always were very informative! Good thread!
Title: Re: All the experienced kiln driers. Solar kiln or power?
Post by: pineywoods on December 12, 2014, 09:44:37 PM
There's a few of us on here that have a hybryd kiln. solar for heat and a small de-humidifier to get rid of the water. No vents as in conventional solar kilns.
works quite well..,50281.0.html
Title: Re: All the experienced kiln driers. Solar kiln or power?
Post by: woodjunky on December 12, 2014, 11:42:21 PM
Thanks guys! You have no idea how much time and effort you saved me. I can tell the experience speaking...

I realized two years ago, all bummed out sitting in my basement. Looked on the wall, and seen all my dusty saws on the shelves. Each saw represented weeks of work I saved to buy. Each one a step closer to the dream of being a great log home builder... Thats when I realized I was just a TOOL! LOL! Just like my sweet saws that can build great things. I am a sweet tool sitting on the shelf... Last year I started chasing houses again. Traveling log home builder... The recent houses are on youtube under Haugen Builders if you want to check them out.

 Anyways, I cant build for myself when I dont have land, money, or materials. So I emptied my account. Bought 3 acres of hardwoods with power, and my sawmill. 6500 total.... I got land and materials now. Still no money LOL.  The TOOL is sharpened up though. Tuned and true. Ready to start cutting some unwanted ash and basswood into timber frame drying shacks. Then after I get a couple extensions, I can timber frame a larger building to woodwork and put my kiln area inside.... After reading your input guys, I've decided to go dehumidification room. Catch some of that lost heat with my workshop, right Gene? Until the money finds me, to buy equipment. I will work with what I have and make drying shacks. Because I learned my lesson the hard way. Everything I own free and clear now days......

On a side note, I have a cool idea for the dry shacks. Im limited right now to about 10' beams on my mill. lts hard to explain, Picture 2 level hip roof. Open between first and second level to pull a little more draft hopefully. With 3' overhangs top and bottom. A 10/12 pitch. I can get 18'x18' floor space inside the posts with two levels of 10' rafters. Three 19' headers are the only beams over 10' in the whole structure. 19s are full span headers/tie, so I can drive through.  Then down the road, I can frame them in and sell the place as a camp complete with timber frame cabins and lodge...

As someone said on another board. Pretty soon every tree is going to look like its dying. And I will be the owner of a stump orchard...LOL. Its a good 3 acres. Lots of trees on 3 acres.... But it could end up a stump orchard if I dont find more land before too long.

Title: Re: All the experienced kiln driers. Solar kiln or power?
Post by: GeneWengert-WoodDoc on December 13, 2014, 09:52:31 PM
Just in case you are tempted to try solar, your climate is not good for that being on the south side of Lake Superior (cold and cloudy), and your latitude is very far north.

When looking at what to dry, understand that you can run the kilns all day, but you only make money when you sell the wood.  So, choose wood that you can sell easily once it is dry.  The last thing you want is some KD lumber sitting around for months.  Of course that also means you need to saw the correct species, thicknesses and grades.

Good luck.  Keep in touch.